Makefile: Remove echoing of kvmtools version file

On every build we report the kvmtool "version" number, which isn't
meaningful at all anymore.

Remove the line from the KVMTOOLS-VERSION-GEN script to drop a
pointless message.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

util/KVMTOOLS-VERSION-GEN

@@ -35,6 +35,5 @@ else
 	VC=unset
 fi
 test "$VN" = "$VC" || {
-	echo >&2 "KVMTOOLS_VERSION = $VN"
 	echo "KVMTOOLS_VERSION = $VN" >$GVF
 }